Technical Field
This disclosure relates to a coupler assembly and method to facilitate alignment of components in power transmission systems, and in some embodiments, is directed to a coupler assembly and method to facilitate meshing of a rack and pinion for high precision and efficient movement of driven components.
Description of the Related Art
High-pressure fluid jets, including high-pressure abrasive waterjets, are used to cut a wide variety of materials in many different industries. Systems for generating high-pressure abrasive waterjets are currently available, such as, for example, the Mach 4™ 5 axis abrasive waterjet system manufactured by Flow International Corporation, the assignee of the present invention. Other examples of abrasive waterjet cutting systems are shown and described in Flow's U.S. Pat. No. 5,643,058, which is incorporated herein by reference. In such systems, high-pressure fluid, typically water, flows through an orifice in a cutting head to form a high-pressure jet, into which abrasive particles are combined as the jet flows through a mixing tube. The high-pressure abrasive waterjet is discharged from the mixing tube and directed toward a workpiece to cut the workpiece along a designated path.
To enable cutting along a designated path, waterjet cutting systems include various motor driven components to move and orient a cutting head in a selected manner. For example, many systems include a bridge assembly that translates along one axis and which supports a tool carriage that is movable along a transverse axis such that cutting head is moveable with respect to an x-y plane. The tool carriage may further enable the cutting head to translate in an axis perpendicular to the x-y plane, as well as include an articulated wrist to adjust an orientation of the cutting head relative to the workpiece.
Translational movement along certain axes can be accomplished via rack and pinion drive systems in which a rotatable pinion meshes with teeth on a linear rack to convert, rotational motion of a motor (e.g., electric rotary motor) to linear motion in a direction parallel to the rack. While systems are typically designed such that the pinion meshes with the rack in an ideal manner, the stack up of machining tolerances and other assembly constraints inevitably introduce variations in mating components which results in misalignment (whether slight or otherwise). Misalignment of the rack and pinion can lead to premature wear and inaccuracies in processed workpieces. In addition, misalignment of the rack and pinion can create excessive noise during operation. To address this problem, shims may be used during assembly between mating components to improve meshing accuracy; however, shimming is a tedious trial by error process that can be prone to error and difficult to repeat consistently.